Multifocal juvenile osteochondritis dissecans of the knee: a case series.

BACKGROUND This retrospective case series reports on a group of patients with multifocal juvenile osteochondritis dissecans (MJOCD) of the knee and discusses demographic data, lesion location, stage, and treatment results. METHODS Records of patients identified with MJOCD of the knee at a single institution were retrospectively reviewed. Demographic, radiographic, and surgical results were recorded. Lesions were descriptively classified and lesions undergoing surgical treatment were staged. Results of operative and nonoperative treatment were recorded. RESULTS Fifty-nine lesions were identified in 28 patients who met the inclusion criteria. There were 22 males (78%) and 6 females (21%). Average age was 11.8 years (males, 6 to 17; females, 10 to 14). Thirty-six (61%) lesions were on the medial femoral condyle (MFC), 19 (32%) on the lateral femoral condyle, 2 (3%) on the trochlea, 1 (2%) on the patella, and 1 (2%) on the anteromedial tibial plateau. Forty-four (74%) lesions required operative treatment. Of the 32 stable lesions managed surgically, 25 (78%) achieved healing with operative treatment. All 12 unstable lesions identified were managed surgically with 5 (41%) healed after the initial operation. Lesions located on the MFC had a significantly higher rate of healing (89%) compared with lateral femoral condyle lesions (37%) (P<0.0001). CONCLUSIONS MJOCD of the knee defines a subset of patients with >1 identified lesion occurring in the same or the contralateral knee. Prevalence of MJOCD of the knee is unknown. A high percentage of these patients require surgical intervention with only one quarter of stable lesions healing with conservative treatment. Healing rates of stable lesions after surgery was nearly twice that of unstable lesions undergoing surgical intervention. Lesions located on the MFC healed at a statistically significant greater rate than other locations within the knee. Sex, age, and associated discoid menisci had no effect on healing prognosis. LEVEL OF EVIDENCE Level IV-case series.